#include<iostream>
#include<vector>
using namespace std;

int peakIndexInMountainArray(vector<int>& arr) {
    int left = 0, right = arr.size() - 1;
    while (left < right) {
        int mid = left + (right - left) / 2;
        if (arr[mid] > arr[mid - 1]) left = mid;
        else right = mid - 1;
    }
    return left;
}

int main()
{
    vector<int>arr = { 0,1,0 };
    peakIndexInMountainArray(arr);
	return 0;
}